The principal objective of this research program is to develop optimized framework and marginal designs of porcelain-fused-to-metal (PFM) restorations which will demonstrate improved resistance to high temperature distortion (creep) and a reduction in transient and residual stress states due to thermal contraction incompatibility effect. The specific aims of the project are to: 1. Calculate transient and residual stress distributions in simulated PFM restorations using finite element stress analysis. 2. Evaluate the high temperature creep resistance of PFM alloys. 3. Conduct thermal shock screening tests on PFM systems as an indicator of potential thermal contraction incompatibility problems. 4. Measure the marginal distortion of PFM crowns as a function of porcelain-metal system design and thermal history. 5. Examine and characterize PFM specimen fracture surfaces. 6. Determine the fracture resistance of PFM specimens with different coping and framework designs. Interfacial and fracture surface examination will employ SEM methods, energy dispersive x-ray analysis, electron diffraction techniques, and Auger, ESCA, and infrared spectroscopy analysis.